EP0888825B1 - Device for painting - Google Patents

Abstract

The method is for treatment of a spray pipe (3) to handle paint of a second colour/type after spraying a first type. A considerable volume of the first paint still in the pipe flows back into its storage container (5). The flow is generated by pref. a scavenging medium or compressed air. During the return flow, a signal-transmitting divider element (29) is positioned in the pipe between paint and medium. Residual paint in the pipe after the return flow of most of it, is pressed into a recycling pipe (11) and a recycling container (12). The pipe, and all components including the atomizer (2), are rinsed with a pulsating solvent and compressed air, and then with compressed air only.

Description

The invention a device for painting according to the preamble of claim 1. Such a device is known from the non-prepublished EP-A-865 830.

Especially when it comes to industrial serial painting usual to use automatic color changing devices, if a series of identical or similar workpieces with different colors should be painted. Such Color changing devices are e.g. also in the DE 43 42 128 A1 shown and described. Since it is imperative it is necessary that at the order point there is a single variety Paint, the line carrying the paint must be and all components that come into contact with the paint in sufficient and an absolute variety to ensure that they are cleaned. The related Effort is very large, but also complicating in addition, considerable amounts of paint are lost, which are in the paint line and / or in related components are located.

The invention is therefore based on the object to create a device by means of which it is possible to save effort and losses when cleaning and providing a paint line and associated Minimize components.

The solution to this task is characterized by the features of claim 1 reached.

According to the invention in the paint line existing paint quantities are not lost and can used again next painting of the color in question become. This is associated with considerable cost savings, with the fact that the length of the Paint lines from the point of view of the cost of the Lacquer no longer matters.

The invention also provides that the in amount of paint in the paint line using a separating element in the area between the atomizer and Color changer via the open color valve in the color changer is pushed back into the feed line, for which purpose the separating element on the atomizer side with a medium - preferably Detergent or compressed air - is applied, the Pressure above the pre-paint from the supply line to Color changer lies.

Further features of the method according to the invention and the associated device go from dependent claims with the description and the drawing.

Fig. 1:

ein Blockschaltbild des Verfahrens beim Lackieren einer ersten Farbe bis zum Lackier-Stop;

Fig. 2:

das Blockschaltbild wie in Fig. 1 beim Zurückdrücken des aus der Lackleitung zu entfernenden Lackes;

Fig. 3:

das Blockschaltbild wie in den Figuren 1 und 2, ebenfalls noch während des Zurückdrückens von zu entfernendem Lack;

Fig. 4:

das Blockschaltbild wie in den Figuren 1 bis 3 bei einem weiteren Reinigungsschritt;

Fig. 5:

eine Ansicht wie in den Figuren 1 bis 4 beim Reinigen der Lackleitung und zugehöriger Komponenten bis zum Ende der Reinigung und

Fig. 6:

im Schnitt sowie in größerem Maßstab und in schematischer Darstellung eine Ansicht einer Einzelheit einer Aufnahmestation für ein Trennelement.

The invention is described below with reference to an embodiment shown in the drawing. Show:

Fig. 1:

a block diagram of the process when painting a first color until the paint stop;

Fig. 2:

the block diagram as in Figure 1 when pushing back the paint to be removed from the paint line.

Fig. 3:

the block diagram as in Figures 1 and 2, also while pushing back paint to be removed;

Fig. 4:

the block diagram as in Figures 1 to 3 in a further cleaning step;

Fig. 5:

a view as in Figures 1 to 4 when cleaning the paint line and associated components until the end of cleaning and

Fig. 6:

in section and on a larger scale and in a schematic representation a view of a detail of a receiving station for a separating element.

A painting system / painting device 1 has on it one, workpiece-side end according to the block diagram in 1 a paint application device / an atomizer 2 on a paint line 3 e.g. with a color changer 4 is connected. The color changer 4 includes any many storage containers 5, 6, 7 and 8 with paint supply lines for paints of different colors / types each with the help of elements not shown under one specified paint form. Controllable with the help Valves 9 are the supply containers 5 to 8 to a paint supply line 10 connectable, which in turn with the paint line 3 is connected.

A disposal line 11 leading to a disposal container 12 leads, is also via a controllable valve 9 connected to the paint supply line 10. same for finally for a detergent supply 13 and a supply line 14 for compressed air, which is also in the form of pulsating compressed air may be present.

Both the disposal line 11 and the detergent supply 13 and the supply line 14 for compressed air are on the paint supply line 10 from the atomizer 2 seen behind the branch points for the storage containers 5 to 8 arranged.

If the paint line 3 including atomizer 2 and the Paint supply line 10 due to a paint or color change must be cleaned, it is first ensured that a substantial part of that in the paint line 3 Paint in its storage container, e.g. in the storage container 5 flows back. This varnish is expedient pushed back. This is done using a Aid that is in the paint line 3 Paint from the paint applicator / atomizer side 2 towards the paint changer 4 and by suitable Switching the controllable valves 9 into the correct storage container 5 pushes. Serves as an expedient 15 a fluid or a push medium that is close to the atomizer 2 from a line 16 via a connection device 17 is entered into the paint line 3. The Connection device 17 comprises a line connection piece 18 to the paint line 3 and a check valve 19, via the the line connector 18 with the line 16 for the Sliding medium is connected.

Appropriately serves as an aid 15 or as a sliding medium a flushing medium or compressed air, which is also in shape of pulsating compressed air can be added.

The supply of line 16 with the aid or the sliding medium in the form of preferably flushing medium takes place from a storage container, not shown in FIG. 1 via a line 20 with the interposition of a Check valve 21 and a control valve 22. The Pressure generator for the compressed air or for the pulsating Compressed air is also not shown in Fig. 1. The for guiding the compressed air line 23 is via a Check valve 24 and a control valve 25 also in the Area of a T-piece 26 connected to line 16.

The connection device 17 in the block diagrams shown, the paint line 3 encompassing device comprises a receiving station 28 for an element 29 which is located in the flow path 30 of the paint line 3. The element 29 is a mechanical cleaning element and / or a Separating element and / or a signal transmitter and is below referred to as "newt 29". It can also be used as a parking station serving receiving station 28 flows around the paint what will be discussed later. The newt 29 is e.g. plastic ball or a cylindrical body with a preferably smooth surface. Its cross section can be the same, smaller or larger than the cross-section of the paint line receiving it 3 or the paint line piece 3 'between the atomizer side arranged receiving station 28 and a second, in or at the color changer 4 arranged second recording station 31st

The paint line piece 3 'between the two recording stations 28 and 31 can be flexible and thus e.g. on Be hose. In this case, the pig 29 should be a higher one Surface hardness and less elasticity than that own flexible hose material.

The second receiving station 31 are also a pig removal device 32 and a pig sensor 33 assigned.

The pig removal device 32 is used to replace the Elementes 29 / Molches 29 and the pig sensor 33 inputs Control signal when the pig 29 is in the line piece 3 'is with him. The pig sensor 33 reports this Passing the pig 29 to the control panel, so that in Depending on this signal, the function valves on Color changer 4, etc. can be switched.

The pig 29 used is designed in shape and material so that he with magnetic, inductive, optical or other sensors can be identified.

Finally, in the paint line 3 or in one of the Paint line pieces 3 'or 3' 'a paint metering device 34 arranged. It can be placed at the beginning or end and is used for dosing the amount of paint to be dispensed in the painting process. In addition, it leaves when backwashing the paint line through appropriate measures residual paints and flushing media in the backward flow direction.

Function and operation of the painting device 1 and Its components for cleaning are as follows.

In the paint shop, paint of a color I flows e.g. from the Storage container 5 through the paint supply line 10 and through all in the paint line pieces 3 ', 3' 'and 3' '' or in the paint line 3 components to the atomizer 2 and will be delivered there. During the painting operation the pig 29 is in its atomizer side Recording station 28, as shown in Fig. 1 is. The same applies to a paint stop after Painting process with the first color.

For cleaning the paint line 3 in the area of the paint line pieces 3 ', 3' 'and essential parts of the paint supply line 10 in the color changer 4 Sliding medium / flushing medium from line 16 into the lacquer line section 3 ' given so that the sliding medium is still in the paint pipe pieces 3 'and 3' 'and in the paint supply line 10 paint located back into the reservoir 5 pushes. The pig 29 is located between the paint 35 and the sliding medium / flushing medium 36, as shown in FIG. 2 is shown. The flow back to the reservoir 5 is achieved by suitable pressures in the line 16 and in the paint supply line 10.

The pig 29 moves in the paint line 3 or in the Paint line section 3 'to the second receiving station 31 and then takes a parking position there, as shown in Fig. 3 is shown.

That in the paint line piece 3 '' and in the paint supply line 10 to the control valve 9 in front of the reservoir 5 residual paint 35 '' in the color changer 4 is at least also partly from pushing medium / flushing medium 36 still pushed back into the storage container 5, whereby this pushing medium / flushing medium 36 in the second receiving station 31 moved past the pig 29. An absolute rest 37 of the paint 35 will eventually be on time Close the control valve 9 and open the to the disposal line 11 leading to the disposal container 12 Control valves 9 via the line piece 10 'from the color changer 4 removed. It is now only there Detergent in the painting device 1 from the color changer 4 up to the receiving station 28.

Now the line section 3 '' 'of the paint line 3 cleaned between atomizer 2 and receiving station 28 become. The detergent supply 13 and the Compressed air supply from line 14 in the color changer 4. With their help the in the line section 3 '' 'and in the atomizer 2 remaining paint 35 '' 'by the atomizer 2 removed. At the same time, the pig 29 moves 4 again from the receiving station 31 into his Parking position in the other receiving station 28, in which he as well as in the receiving station 31 of flushing medium 36 can flow around.

At the end of the cleaning process, the entire rinsing medium 36 from the paint line 3 or the individual paint pipe sections with compressed air from the color changer 4 Supply line 14 removed, with paint residue 35 '' 'can flow out of the atomizer 2. This too The situation is shown in the block diagram according to FIG. 5. It finally understands that all valves, pumps and other units work in a coordinated manner need to clean the paint line 3 and their provision for a color and / or variety change largely without loss of the paint line 3 paint is feasible.

The two serving as parking stations for the newt 29 Pickup stations 28 and 31 each have the arrangement shown in FIG. 6 a chamber 40 whose diameter D and length L are each larger than the corresponding dimensions of the Molches 29. Also protrudes into the interior of chamber 40 e.g. pin-shaped stop 41, which prevents that the pig 29 on one end face 42 of the chamber 40 is present when a flow medium, namely paint 35 or Flushing medium 36 in the direction of arrows a through the chamber 40 stream.

Due to the dimensions and the shape of the Chamber 40 and e.g. is also achieved by the stop 41 that the pig 29 does not close the chamber 40 can and always get a flow path 30 through the chamber 40 remains.

On the one opposite the stop 41 or one end face 42 The chamber 40 preferably has one end conical transition 43 to an outlet opening 44 through the pig 29 get into the chamber 40 and so do they again with the corresponding flow direction of the flow medium (Paint 35 or flushing medium 36) can leave. The The diameter of the outlet opening 44 is less than that Diameter D of chamber 40 and corresponds to the inside diameter of the paint line piece 3 ', which in a suitable and not shown in Fig. 6 to the outlet opening 44 is connected.

The chamber 40 has at its stop 41 or a second at its end belonging to the end face 42 Outlet opening 45, which at the receiving station 28 with the line piece 3, 3 'leading to the atomizer 2 and at the recording station 31 with the leading to the color changer 4 Line piece 3 "is connected. Advantageously, the The diameter of the outlet opening 45 is smaller than that of the outlet opening 44th

The invention is not based on that specifically shown in the figures Embodiment limited, rather are Modifications are still possible without the basic Deviate inventive ideas. This includes in particular also that the method can be carried out without a pig 29 in the sense of a separating element between the different media is provided. The respective limit between paint 35 on the one hand and sliding medium 36 on the other can also be done by volume measurement so that the in the end, residual paint to be disposed of at the color changer 4 37 recognized and directed into the disposal line 11 can.

6 also shows only one embodiment of an element 29 in the form of an elongated, approximately cylindrical Body with a preferably frustoconical end. It consists of a steel core 29 'and a plastic jacket 29 ''. The steel core 29 'serves as a signal generator in Connection with a sensor. Furthermore, the jacket 29 " according to the embodiment at both ends and at his Circumferential outward annular beads 29 '' ' or ribs or lips for cleaning or stripping of the paint / color on the inner contour of the person receiving it Hose or pipe. Its dimensions and Tolerances are related to the internal dimensions and tolerances of the Adjusted hose or tube. Its length can be a few Millimeters or in some cases also a few centimeters. The jacket 29 '' suitably consists of pom, d. H. from a homopolymer such as the one under the trademark "Delrin" plastic on the market. Other materials for the jacket are also conceivable, to ensure good contact with the inner wall of the hose or To reach Rohres.

The atomizer 2 can be any application device and in particular a manually operated spray gun his.

Furthermore, the detergent line (line 16) can also be used as an alternative can be connected manually to a fixed connection. This is particularly advantageous for hand-held spray guns, because then this line is not on the gun, but on the gun flushing station can be attached.

Instead of lacquer and / or paint, another, any coating agent using the device 1 can be processed. The invention is therefore not based on limited the use of paint.

It is essential that at least part of the coating agent or the paint with the help of an atomizer in the line 3 pressed sliding medium, preferably using detergent or using compressed air a direction opposite to that applicable during processing Flow direction pushed back towards the reservoir is or flows, with an additional element 29 is arranged in front of the sliding medium 36, so that the Element 29 moved in the flow. The element 29 can an exclusively signaling element and / or one at the same time, i.e. the liquid column in front and the liquid column behind the element 29 more or less dense separating element. At least temporarily it also becomes in the flow / in the flowing medium arranged when the coating agent in the direction of Storage container 5 flows and at least partially up to is pushed back. The element 29 or the separating element can be provided with or without elastic sealing lips and made of different materials, e.g. made of plastic, metal, rubber, foam and / or Combinations of these materials exist.

Depending on the elasticity of the line 3, this can Element 29 itself may be more or less elastic if it ensure an adequate seal to the wall of line 3 should.

The transmission of signals to determine its location can be electrical - inductive or by means of magnetic forces respectively. However, it is not limited to this. The Element 29 can only have a signaling function and / or at the same time the space in front and the space behind the element 29 have a sealing function. For safety reasons it can expediently before the backflow process shortly before the end of the coating agent Liquid column are arranged. A little The rest must then be disposed of. The element 29 therefore does not necessarily define an exact boundary between the one to be used further and to be regained Coating agent on the one hand and the sliding medium 36 on the other hand.

The element 29 (pig) is a according to the embodiment elongated, approximately cylindrical body with a preferably frustoconical end. It exists according to the embodiment from a steel core 29 'and a plastic jacket 29 ''. The steel core 29 'serves as a signal generator in connection with a sensor.

According to the exemplary embodiment, the jacket 29 ″ points to both Ends as well as ring-shaped on its periphery Beads 29 '' 'or ribs or lips for cleaning or to wipe off the coating agent / lacquer / paint on the inner contour of the hose receiving it or Pipe on. Its dimensions and tolerances are close to that Internal dimensions and tolerances of the hose or tube customized. Its length can range from a few millimeters to a few Centimeters.

The jacket 29 '' advantageously consists of a homopolymer (POM), e.g. under the trademark "Delerin" plastic on the market. Other materials are basically also conceivable for the coat a good fit on the inner wall of the hose or tube to reach.

In principle, it is also not absolutely necessary that essential parts of the coating agent in the original Flow back the reservoir. The one to be won again and coating agents to be processed also flow to at least one other location and accordingly or to do this by at least one other / different line be performed. Such a different place can e.g. another processing point or another atomizer his. To reach it, the coating agent must be at least one piece in the direction of the storage container 5 move.

The variants described show that the invention not on the possibilities shown in the figures is limited and that modifications are still possible without that determined by the claims Deviate protection area.

Claims (5)

1. Painting device with a colour changeover device (4) which comprises at least two storage containers (5 to 8) for different paints and from which a paint duct (3) leads to at least one spray equipment (2) or atomiser, as well as with equipment for controlling, switching and pumping the paint (35) and with equipment for automatic cleaning of all components in the case of a colour change, wherein at least a substantial part of the paint (35) still disposed in the paint duct (3) at the conclusion of the painting process can be forced back into its storage container (5) with use of a scraper-like element and a connecting element (17) for a displacement medium is provided in the paint duct (3) between atomiser (2) and colour changeover device (4), characterised in that

   a) a respective receiving station (28, 31) for the scraper-like element (29) movable between the two receiving stations (28, 31) in the paint duct (3) is associated with each of the atomiser (2) and the paint changeover device (4) and

   b) the two receiving stations (28, 31) serving as park stations for the scraper-like element (29) each have a respective chamber (40), the diameter (D) of which and the length (L) are larger than the respectively corresponding dimensions of the scraper (29) in such a manner that the chamber cannot be closed by the scraper-like element and a flow path through the chambers is always maintained.
2. Painting device according to claim 1, characterised in that an abutment (41) projects into the chamber (40) in such a manner that the scraper-like element (29) does not close the chamber (40) and a flow path (30) is always maintained through the chamber (40).
3. Painting device according to claim 1 and 2, characterised in that the scraper-like element (29) has a cylindrical body with frusto-conical ends and with beads.
4. Painting device according to at least one of the preceding claims, characterised in that the scraper-like element (29) has a steel core (29') and a synthetic material casing (29"), wherein the steel core (29') serves at the same time as a signal transmitter in conjunction with a sensor.
5. Painting device according to at least one of the preceding claims, characterised in that the steel core (29') projects beyond an end face of the scraper-like element (29).

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